The highly advanced technological fields bring on the quick development of networks. To use different networks, a large quantity of data transmission connectors is required. In the early stage of setting up networks, the data transmission connectors for accessing to the networks were not provided with any protective covers and were therefore subject to damages caused by invaded foreign matters or unauthorized use of them. It is therefore tried by the inventor to develop a protection module for data transmission connector, so as to protect a data transmission connector against damages caused by maliciously applied force or improper use of it.